The present invention generally relates to beverage dispensers. More particularly, the present invention relates to a post-mix beverage dispenser for agitated or whipped beverages.
There are presently a number of popular beverages sold in restaurants, snack shops, amusement parks, fast food outlets, and other establishments throughout the world. Some of these beverages are served in a whipped or foamed condition. That is, the beverage is agitated or whipped in the dispensing process to give the served beverage a foamy, froth texture. Typically, these beverages are made from a combination of a concentrate and a diluent, usually water. The concentrate by itself generally does not require refrigeration and has a shelf life of several months to over a year. However, when mixed with a diluent such as water or exposed to air, the combined beverage usually requires refrigeration to retard bacterial growth.
For years, two basic type of fountain dispensers have been available to the trade, referred to respectively as “pre-mix” and “post-mix” dispensers.
Pre-mix dispensers mix a syrup concentrate and water to provide a finished beverage which is then stored in a holding tank until dispensed through a facet located on the dispenser. However, such pre-mix dispensers suffer from a number of disadvantages. Even with refrigeration, some bacterial growth is present. Consequently, after a period of time, typically a few days, any remaining pre-mix beverage should be discarded to maintain healthful quality and pleasing beverage taste. Thus, it is necessary to disassemble and clean the whipping assembly on a daily basis to remove accumulated beverage residue remaining in the whipping apparatus.
Post-mix dispensers do not pre-mix and store the syrup and water. Instead the syrup and water conveyed by separate conduits to a dispenser housing, sometimes referred to as valves or heads, and then mixed while being dispensed through the usual spout on the housing. It has been found that the majority of the mixing in such soft drink dispensers actually occurs in the beverage cup as the beverage is being dispensed as the syrup and water are merely dropped over a diffuser such that a small amount of mixing occurs in the spout, and the final mixing occurring in the beverage cup. The syrup may be stored remotely from the dispenser housing in a metallic cylinder, or in a collapsible plastic bag in a cardboard box, or any other suitable storage medium. The water source may simply be the available municipal water line. Post-mix dispensers overcome, to a great extent, the disadvantages suffered by the pre-mix dispensers. Accordingly, the majority of soft drinks and non-carbonated beverages sold in restaurants and fast-food businesses utilize post-mix dispensers.
In the early 1980's, Orange Bang, Inc. designed a dispenser for a whipped beverage comprising a specially designed plastic mixing block 1, as shown in FIG. 1. The mixing block 1 included a generally hemispherically shaped mixing chamber 2 cut-out therefrom. A syrup concentrate conduit 3 was formed in the block 1 such that it extended between the mixing chamber 2 and a solenoid valve 4 which controlled the delivery of the pressurized syrup concentrate. Similarly, a conduit 5 was formed in the block which was in fluid communication with the mixing chamber 2 and another solenoid valve 6 for controlling the amount of pressurized water which was delivered. The concentrate and water conduits 3 and 5 were angled with respect to one another such that the syrup and water would be ejected at angles which would intersect at a given point to create the frothed beverage. It was discovered that the mixing chamber 2 had to be vented to allow air to be introduced into the mixing chamber 2 and allow the concentrate and water to whip or froth. Accordingly, a vent conduit 8 was formed in the block 1. It was also found that whip-gain was improved and the possibility of the beverage entering the vent conduit 8 virtually eliminated by the addition of a metal tube 7 within the vent conduit 8 and extending into the water conduit 5. As the water cascaded over the end of the tube 7, a venturi effect was created allowing air to be drawn into the water stream, while preventing the back flow of beverage through the air vent 8 and out of the exterior of the block 1 of the dispenser. Other conduits 9 such as for electrical leads, stream control devices, etc. were formed in the mixing block 1.
U.S. Pat. No. 4,676,401 to Fox et al. discloses an improvement on this design, wherein a mixing paddle operated by a motor is introduced into the mixing chamber to improve the whip-gain of the whipped beverage.
U.S. Pat. No. 6,305,269 to Stratton, discloses a slight variation to the initial Orange Bang, Inc. beverage dispenser. To improve whip-gain, Stratton discloses the use of a uniquely configured water injection nozzle having a tube with a flattened end portion defining an elongated water injection port extending into the mixing chamber. Such specialized water injection nozzle provided sufficient whip-gain. However, the Stratton dispensing apparatus also required the specially designed plastic mixing block with the various passageways and chambers, including the air passage and for allowing air to enter the mixing chamber. Another problem with all of these devices is that, due to their specialized design, they effectively served as a stand-alone dispenser often placed next to traditional carbonated beverage dispensing banks.
Accordingly, there is a continuing need for an apparatus for preparing and dispensing whipped beverages which does not require the use of a plastic mixing block having chambers and conduits formed therein. What is further needed is such a dispenser which could be incorporated into a traditional bank of soft drink dispensers. Such a dispenser should provide optimum whip-gain such that a lower amount of syrup is required for the beverage. The present invention fulfills these needs, and provides other related advantages.